BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Cooper's Hawk Population Trend in Illinois

All statesGeneralists

Cooper's Hawk in Illinois has surged: up 982% on the route-weighted index since 1980.

+982%Since 1980TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
90Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
40YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cooper's Hawk Trends in IllinoisNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Cooper's Hawk has surged in Illinois: up 982% on the route-weighted index since 1980.

Cooper's Hawk Population Forecast in Illinois

If the recent trend holds, Cooper's Hawk in Illinois is projected to stay roughly flat through 2029, near 0.23 (95% range 0.16–0.31). A 5-year backtest shows a typical error of ±27.4%, with 80% of held-out values landing inside the 95% band.

+10%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.23Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.16–0.3195% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±27.4%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Cooper's Hawk in Illinois is projected to stay roughly flat through 2029, near 0.23 (95% range 0.16–0.31). A 5-year backtest shows a typical error of ±27.4%, with 80% of held-out values landing inside the 95% band.19782029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.210.140.29
20260.220.140.29
20270.220.150.30
20280.230.150.30
20290.230.160.31

Cooper's Hawk Survey Routes in Illinois

Routes recording Cooper's Hawk in Illinois.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Wayne420241992
Columbia320222001
Kell320082007
Mill Creek220191998
Janesville220242005
Humboldt220222009
Olney220041992
Troy Grove220222015
Nilwood220122012
York220171993
Dudleyville220152002
Guilford120171978
Holcomb120151998
Cherry Val119981992
Barrington119931990
Itasca120242012
Geneseo120171988
Putnam120241998
Sheffield120191995
Buda120232023
Streator120222016
Essex120242014
Newark120152011
Sherburnvill120132011
New Lenox120161993

Cooper's Hawk Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.